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D J Ross

Publications and source records attributed to D J Ross.

At least 19 recordsLinked to original sources
PubMed2002

A field based evaluation of household arsenic removal technologies for the treatment of drinking water.

Seven household treatment technologies for the removal of arsenic (Alcan, BUET, DPHE/DANIDA, Garnet, Sono, Stevens, Tetrahedron) were each evaluated using water from 63 different tube wells taken from 3 different regions of Bangladesh. The technologies that were evaluated were chosen from those that appeared user friendly, readily available and whose promoters were open to participate in the study. Arsenic concentrations in feed and treated waters were analysed by the PeCo 75 arsenic field test kit, AA-hydride generation and ICP-AES. Feed water arsenic concentrations were found to be up to 600 microg l(-1). The more advanced treatment methods using: activated alumina (Alcan, BUET); metallic iron (Sono); anionic exchange resin (Tetrahedron) and iron coagulation (Stevens) were found to be most easily used and efficiently reduced arsenic concentrations to below the Bangladesh drinking water standard (0.05 mg As l(-1)). The use of aluminium sulphate coagulants and permanganate oxidants in the DPHE/DANIDA technology introduced unacceptably high concentrations of aluminium and manganese into the treated waters and are not recommended in household water treatment applications. While arseric concentrations were initially considered to be of paramount importance, it became clear that such technologies can increase the risk of bacterial contamination in the treated water and this needs serious consideration as this could create a hazard much greater than the arsenic contained in the water. Ground waters sampled during the course of this study were mostly found to be bacteria free. To minimize any risks relating to bacterial contamination the addition of hypochlorite or the boiling of water is necessary.

Aluminum Oxide↗
PubMed2001

Kin discrimination in cooperatively breeding long-tailed tits.

Long-tailed tits Aegithalos caudatus are cooperative breeders in which helpers exhibit a kin preference in their cooperative behaviour. We investigated the mechanism through which this preference is achieved by first conducting an experiment for testing whether breeders could recognize the calls of their relatives while controlling for spatial effects. We found that there were significant differences in the responses of breeders to the vocalizations of kin and non-kin, suggesting that vocal cues may be used for kin recognition. We conducted a second experiment in order to investigate whether recognition is achieved on the basis of relatedness per se or through association. Nestlings were cross-fostered between unrelated broods in order to create broods composed of true and foster siblings. In subsequent years, survivors from experimental broods did not discriminate between true and fostered siblings when making helping decisions, indicating that recognition is learned and not genetically determined. We discuss the effectiveness of learning through association as an indirect cue to kinship.

Animals↗
PubMed2001

Critical role for the chemokine MCP-1/CCR2 in the pathogenesis of bronchiolitis obliterans syndrome.

Bronchiolitis obliterans syndrome (BOS) is the major limitation to survival after lung transplantation. Acute rejection, its main risk factor, is characterized by perivascular/bronchiolar leukocyte infiltration. BOS is characterized by persistent peribronchiolar leukocyte recruitment leading to airway fibrosis and obliteration. The specific mechanism(s) by which these leukocytes are recruited are unknown. Because MCP-1, acting through its receptor CCR2, is a potent mononuclear cell chemoattractant, we hypothesized that expression of this chemokine during an allogeneic-response promotes persistent recruitment of leukocytes and, ultimately, rejection. We found that elevated levels of biologically active MCP-1 in human bronchial lavage fluid (BALF) were associated with the continuum from acute to chronic allograft rejection. Translational studies in a murine model of BOS demonstrated increased MCP-1 expression paralleling mononuclear cell recruitment and CCR2 expression. Loss of MCP-1/CCR2 signaling, as seen in CCR2(-/-) mice or in WT mice treated with neutralizing antibodies to MCP-1, significantly reduced recruitment of mononuclear phagocytes following tracheal transplantation and led to attenuation of BOS. Lymphocyte infiltration was not reduced under these conditions. We suggest that MCP-1/CCR2 signaling plays an important role in recruitment of mononuclear phagocytes, a pivotal event in the pathogenesis of BOS.

Animals↗
PubMed2001

Case-referent survey of young adults with mesothelioma: I. Lung fibre analyses.

OBJECTIVES: Our study aimed to determine the lung tissue concentration of asbestos and other mineral fibres by type and length in persons with mesothelioma aged 50 yr or less at time of diagnosis, compared to controls of similar age and geographical region. In this age group it was thought that most, but not all, work-related exposures would have been since 1970, when the importation of crocidolite, but not amosite, was virtually eliminated. METHODS: Eligible cases were sought from recent reports by chest physicians to the SWORD occupational disease surveillance scheme. Lung tissue samples were obtained at autopsy from 69 male and four female cases, and mineral fibres identified, sized and counted by electron microscopy. Fibre concentrations per microg dry tissue were compared with similar estimates from a control series of autopsies of sudden or accidental deaths. Unadjusted, and adjusted odds ratios calculated by logistic regression, assessed relative risk in relation to fibre type, length and concentration. RESULTS: Unadjusted and adjusted odds ratios increased steadily with concentration of crocidolite, amosite, tremolite and all amphiboles combined. There was also some increase with chrysotile, but well short of statistical significance. Incremental risk examined in a linear model was as highly significant for all amphiboles together as individually. Short, medium and long amphibole fibres were all associated with increased risk in relation to length. Mullite and iron fibres were significant predictors of mesothelioma when considered without adjustment for confounding by amphiboles, but, after adjustment, were weak and far from statistically significant. CONCLUSIONS: In this young age group, amosite and crocidolite fibres could account for about 80% of cases of mesothelioma, and tremolite for some 7%. The contribution of chrysotile, because of low biopersistence, cannot be reliably assessed at autopsy, but to the extent that tremolite is a valid marker, our results suggest that it was small. The steep linear trend in odds ratio shown by amphiboles combined indicates that their effects may be additive, with increased risk from the lowest detectable fibre level. Non-asbestos mineral fibres probably made no contribution to this disease. Contrary to expectation, however, some 90% of cases were in men who had started work before 1970; this was so whether or not amosite or crocidolite was found in lung tissue.

Adult↗
PubMed2001

Case-referent survey of young adults with mesothelioma: II. Occupational analyses.

OBJECTIVES: Our study aimed to identify occupations at increased risk of developing mesothelioma in persons aged 50 yr or less, and to relate these occupations to lung tissue concentration of asbestos fibres by type. In this age group it was thought that most, but not all, work-related exposures would have been since 1970, when the importation of crocidolite, but not amosite, was virtually eliminated. METHODS: Eligible cases were sought from recent reports by chest physicians to the SWORD occupational disease surveillance scheme. Work histories were obtained for 115 men and 13 women, usually with the help of the chest physicians or coroners. Jobs were coded by the Office of National Statistics, so that the observed years spent in each occupation could be compared with expected values from census data, 1960-90. Lung tissue samples were obtained at autopsy from 69 male and four female cases, and mineral fibres identified, sized and counted by electron microscopy. RESULTS: Of 37 industrial occupations analysed, odds ratios were significantly raised in eight: five in the construction industry and the others in shipbuilding, the manufacture of cement products and the manufacture of non-metallic mineral products (including asbestos). The concentrations in lung of crocidolite and amosite fibres, which together could account for 80-90% of cases, did not differ between occupational categories; those for amosite were appreciably higher than for crocidolite. Tremolite fibres were rarely found. CONCLUSION: Mesothelioma in this young age group is dominated by carpenters, plumbers, electricians and insulators in the construction industry, and is mainly attributable to amphibole exposure. Work in shipbuilding and manufacture of mineral products was less important than in earlier studies. Contrary to expectation, however, some 90% of cases were in men who had started work before 1970.

Adult↗
PubMed2000

Divorce in cooperatively breeding long-tailed tits: a consequence of inbreeding avoidance?

The decision of whether to divorce a breeding partner between reproductive attempts can significantly affect individual fitness. In this paper, we report that 63% of surviving pairs of long-tailed tits Aegithalos caudatus divorced between years. We examine three likely explanations for the high divorce rate in this cooperative breeder. The 'better option' hypothesis predicts that divorce and re-pairing increases an individual's reproductive success. However, divorcees did not secure better partners or more helpers and there was no improvement in their reproductive success following divorce. The 'inbreeding avoidance' hypothesis predicts that females should disperse from their family group to avoid breeding with philopatric sons. The observed pattern of divorce was consistent with this hypothesis because, in contrast to the usual avian pattern, divorce was typical for successful pairs (81%) and less frequent in unsuccessful pairs (36-43%). The 'forced divorce' hypothesis predicts that divorce increases as the number of competitors increases. The pattern of divorce among failed breeders was consistent with this hypothesis, but it fails to explain the overall occurrence of divorce because divorcees rarely re-paired with their partners' closest competitors. We discuss long-tailed tits' unique association between divorce and reproductive success in the context of dispersal strategies for inbreeding avoidance.

Animals↗
PubMed1999

Lung allograft dysfunction correlates with gamma-interferon gene expression in bronchoalveolar lavage.

BACKGROUND: Preceding episodes of acute cellular rejection (ACR) may predispose lung allografts to the subsequent development of irreversible dysfunction or bronchiolitis obliterans syndrome (BOS). Other histologic patterns such as bronchiolitis obliterans with organizing pneumonia (BOOP), organizing pneumonia, lymphocytic bronchiolitis and diffuse alveolar damage (DAD) may also adversely affect allograft function. We have previously reported the predominant expression of Th1 cytokines (IL-2 and interferon gamma) in rejecting and Th2 (IL-10) in a tolerant model of rat lung transplantation. Here we correlate the "Th1/Th2 paradigm" in clinical lung transplantation with histologic findings and assess the effect on serial spirometric function. METHODS: We examined the mRNA expression of IL-2, interferon gamma, IL-10 and ICAM-1 in 53 bronchoalveolar lavage (BAL) specimens from 23 lung transplant (LT) recipients utilizing qualitative "nested" reverse transcriptase polymerase chain reaction (RT-PCR). We also measured IgG1 and IgG2 levels in 44 BAL specimens by ELISA. The mRNA expression for cytokines, ICAM-1 and the IgG2/IgG1 ratios were correlated with the presence or absence of ACR and alternate "histologic patterns". Serial spirometry were analyzed for the 2-3 month interval before bronchoscopic (FOB) assessment to derive "baseline" forced expiratory volume-one second (FEV1) values. The change in FEV1 coincident with (deltaFEV1 pre) and for the 2-3 month interval subsequent to (deltaFEV1 post) FOB were expressed relative to "baseline" spirometric indexes. RESULTS: Detection of mRNA for interferon gamma and ICAM-1 correlated significantly with ACR, whereas IL-2 and IL-10 expression did not correlate. IL-10 was virtually "ubiquitous" in most BAL samples irrespective of the presence or absence of ACR. The highest correlation was observed with interferon gamma for acute cellular rejection whereupon the sensitivity was 77.7%, specificity 87.7%, positive predictive value 73.6% and negative predictive value 88.2%, although for ICAM-1 these values were 75%, 65.7%, 50.0% and 85.0%, respectively. Nevertheless, 4 of 5 episodes of respiratory tract infection (bacterial, CMV, Aspergillus spp.) were similarly associated with cytokine mRNA. The ratios of IgG2 to IgG1, a reflection of Th1/Th2 influence, were not statistically different when analyzed for the presence or absence of ACR (0.91+/-0.53 vs. 1.02+/-0.70, respectively; p = NS). By analysis of FEV1 trends, expression of interferon gamma was associated with a greater and persistent decrement (deltaFEV1 pre: -0.265+/-0.78 liters, and post: -0.236+/-0.1161; mean +/- SE) than ACR in the absence of interferon gamma expression (+0.158 +/- +0.065 and +0.236+/-0.007 liters, respectively) (Student-Newman-Keuls, p<.05). CONCLUSION: Our findings suggest that interferon gamma mRNA expression and ICAM-1 may be valuable in both the diagnosis and prognosis for lung allograft ACR. IL-10, a Th2 cytokine, was locally expressed both in the presence and absence of ACR. Expression of mRNA for interferon y in BAL and, to a lesser extent ICAM-1, were associated with increased lung allograft dysfunction. Whether BAL cytokine "immunosurveillance" would complement or possibly supplant a specific "histologic pattern" and thereby direct different therapies after lung transplantation, may be potentially rewarding areas of further investigation.

Acute Disease↗
PubMed1998

Health and employment after a diagnosis of occupational asthma: a descriptive study.

The objectives of this study were to describe changes in asthma and employment after diagnoses of occupational asthma reported to the SWORD project. Questionnaires were sent to 312 physicians for all 1,940 cases of occupational asthma reported from 1989-92; 1,769 (91%) were returned but information was available for only 1,317 (68%). Of patients reported by occupational physicians, 45% had recovered from asthma compared to only 14% of those reported by chest physicians (excluding medicolegal cases), presumably because of differences in severity. Proportions with the same employer were 49% and 48% respectively. Patients exposed for a year or more after diagnosis recovered from asthma less frequently but were more often employed than those exposed for less than a year. Among those whose asthma was attributed to high molecular weight agents, smokers had developed asthma earlier after exposure began than others but had the best prognosis. Asthma developed following a single high exposure in 18 cases (2%), of which 13 were to irritants and five to known sensitizers.

Adolescent↗
PubMed1998

SWORD '97: surveillance of work-related and occupational respiratory disease in the UK.

SWORD is one of seven clinically based reporting schemes which together now provide almost comprehensive coverage of occupational diseases across the UK. Although SWORD is now in its tenth year, participation rates remain high. Of an estimated 3,903 new cases seen this year, 1,031 (26%) were of occupational asthma, 978 (25%) of mesothelioma, 794 (20%) of non-malignant pleural disease, 336 (9%) of pneumoconiosis and 233 (6%) of inhalation accidents. Incidence rates of occupational asthma were generally highest among workers in the manufacture of wood products, textiles and food (particularly grain products and crustaceans) and additionally, in the production of precious and non-ferrous metals, rubber goods, detergents and perfumes, and in mining. Health care workers were noted to have a surprisingly high incidence of inhalation accidents. Occupational asthma attributed to latex has increased dramatically; the highest rates are among laboratory technicians, shoe workers and health care workers.

Humans↗
PubMed1998

Cellular adaptations of skeletal muscles to cyclosporine.

The aim of this study was to evaluate the cellular response of the diaphragm, extensor digitorum longus (EDL), and soleus (Sol) muscles to clinically relevant doses of cyclosporine administered to male rats over 4 wk. Control rats were provided with vehicle only. Muscle fiber types, cross-sectional areas, indexes of capillarity, and succinate dehydrogenase (SDH) activity were determined by quantitative histochemistry. Myosin heavy chain isoforms were identified by SDS-PAGE, and their proportions were measured by scanning densitometry. Serum cyclosporine level, 20-24 h after the last dose of cyclosporine, was 145 +/- 81 ng/ml. Final body weight and muscle mass were similar between the cyclosporine and control groups. In the diaphragm, EDL, and Sol, no differences were observed between the groups with regard to fiber type proportions, fiber cross-sectional areas, and proportions of myosin heavy chain isoforms. In the EDL, reductions, both in SDH activity in type I, IIx, and IIb fibers (-26 to -37%) and in indexes of capillarity (-18 to -37%), were noted. In the Sol, SDH activity and capillarity were similar between the groups. In the diaphragm of cyclosporine-treated rats, there was significant reduction in the number of capillaries around individual fibers (-5%), whereas levels of SDH activity tended to be lower. This suggests that activation history may in part determine muscle-specific responses to cyclosporine. We speculate that reduced oxidative activity and capillarity of some limb muscles contribute to reduced exercise capacity and the "deconditioned state" observed in patients receiving cyclosporine after successful solid-organ transplantation.

Animals↗
PubMed1998

Occupationally acquired infectious disease in the United Kingdom: 1996 to 1997.

The incidence of occupationally acquired infectious diseases, has, up to now, been unknown. A reporting scheme for consultants in communicable disease control (CCDCs) (and their equivalents) throughout the United Kingdom was set up in October 1996 to estimate its extent. Monthly reporting cards were sent to CCDCs asking for brief details of all new cases of occupationally acquired infectious disease seen by them. Between October 1996 and September 1997, 1037 new cases were notified by CCDCs. The highest rates were among employees in food production and catering, farming, and among care workers, particularly in residential homes. During the same period an estimated 257 cases were reported in comparable surveillance schemes by chest physicians, occupational physicians and dermatologists. These figures probably underestimate the number of infections acquired in association with work substantially, and highlight diarrhoeal disease as the commonest problem.

Adolescent↗
PubMed1998

Mycophenolate mofetil versus azathioprine immunosuppressive regimens after lung transplantation: preliminary experience.

BACKGROUND: Mycophenolate mofetil reduces episodes of biopsy-proven acute cellular rejection or treatment failure in the first year after kidney transplantation; however, limited data exist regarding the efficacy after lung transplantation. METHODS: In a 2-center, nonrandomized concurrent cohort study (level III evidence), we analyzed the incidence of biopsy-proven acute cellular rejection (International Society for Heart and Lung Transplantation grade > or=A2) and decrement in pulmonary function during the first 12 months after successful lung transplantation. All patients received induction immunosuppression with antithymocyte globulin (< or=5 days' duration), cyclosporine and prednisone, in addition to either mycophenolate mofetil (2.0 g/d) [n=11] or azathioprine (1 to 2 mg/kg per day) [n=11]. RESULTS: During the first 12 months after lung transplantation, the mycophenolate mofetil group experienced significantly fewer episodes of acute cellular rejection than the azathioprine group (0.26+/-0.34 vs 0.72+/-0.43 episodes/100 patient-days [mean+/-SD], p < 0.01; 95% CI for the difference=0.126 to 0.813). The change in forced expiratory volume -1 second [deltaFEV1] (liters) between the 3rd and 12th months after lung transplantation was analyzed for the two treatment groups. For this interval, deltaFEV1 for the mycophenolate mofetil group was +0.158+/-0.497 L vs -0.281+/-0.406 L for the azathioprine group (p < 0.05; 95% CI for difference=+0.0356 to 0.843). During the first year, there was 1 death in each group attributed to bronchiolitis obliterans syndrome with concurrent pneumonia. There were no differences in incidence of cytomegalovirus or bacterial infections between the treatment groups; however, a higher prevalence of aspergillus sp airway colonization in bronchoalveolar lavage fluid was observed for the mycophenolate mofetil group (p < .05). The prevalence of bronchiolitis obliterans syndrome at 12 months was 36% for the azathioprine group vs 18% for the mycophenolate mofetil group (p=NS). CONCLUSIONS: Our preliminary experience with mycophenolate mofetil after lung transplantation suggests a decreased incidence of biopsy-proven acute cellular rejection. Furthermore, less decline in FEV1 after 12 months may suggest a reduced incidence or delayed onset for development of bronchiolitis obliterans syndrome. Prospective randomized trials with low beta error (level I evidence) should be performed to assess the efficacy of mycophenolate mofetil vis-à-vis acute allograft rejection and bronchiolitis obliterans syndrome.

Azathioprine↗
PubMed1997

FK 506 'rescue' immunosuppression for obliterative bronchiolitis after lung transplantation.

PRELIMINARY EXPERIENCE: In a consecutive case series (level V evidence) involving 10 recipients of unilateral lung transplantation (LT) with bronchiolitis obliterans, in conjunction with Fujisawa protocol 93-0-003, the physiologic responses to FK 506 (tacrolimus) "rescue" immunosuppression were assessed. Recipients were 22+/-18 months post-LT and demonstrated progressive allograft dysfunction that was refractory to pulsed-dose methylprednisolone therapy. All recipients received induction immunosuppression with Minnesota antilymphocyte globulin (10 to 15 mg/kg/d) for 5 to 10 days, cyclosporine (CsA) (whole-blood Abbott TDX fluorescence polarization immunoassay (Abbott Inc, Abbott Park, IL)=600 to 800 ng/mL), azathioprine (2 mg/kg/d), and prednisone (tapered to 0.2 mg/kg/d). The "rescue" regimen consisted of oral FK 506 adjusted to maintain a whole-blood Abbott IMX microparticle enzyme immunoassay (Abbott Inc, Abbott Park, IL) of 10 to 15 ng/mL with an initial increase in prednisone (1.0 mg/kg/d) during conversion that was subsequently tapered to 0.2 mg/kg/d. Spirometry was performed monthly in accordance with accepted American Thoracic Society criteria. Recipients were classified in accordance with the International Society for Heart and Lung Transplantation (ISHLT) "Working Formulation for Standardization of Nomenclature and for Clinical Staging of Chronic Dysfunction in Lung Allografts" as stages Ib (n=2), IIb (n=4), and IIIb (n=4) upon entry to the protocol. The deltaFEV1/month relationships during CsA- and FK 506-based regimens were analyzed by linear regression and compared by signed rank test (p<0.05). RESULTS: The deltaFEV1/month slopes were -0.0687+/-0.0221 and +0.0300+/-0.033 L/mo (mean+/-SEM) for CsA and FK 506, respectively (p=0.037). Although no significant spirometric improvement was noted in most recipients, no further decline in FEV1 occurred after conversion to FK 506. Recipients with less severe chronic dysfunction (ie, obliterative bronchiolitis [OB] stages Ib and IIb) stabilized their spirometric indexes at higher levels. Two recipients with OB stage IIIb died of hypercapnic respiratory failure at 6 and 8 months after conversion. CONCLUSIONS: The deltaFEV1/mo slopes stabilized after FK 506 conversion. Earlier conversion may be beneficial in stabilizing FEV1 at a higher plateau. Significant economic impact may be anticipated with FK 506 compared to alternative cytolytic strategies for OB. However, multicenter prospective controlled investigations are necessary to further address the potential role of FK 506 after LT (level I evidence). Furthermore, the ISHLT "Staging of OB Syndrome" may have significant clinical implications vis-à-vis prognosis and potential therapies.

Bronchiolitis Obliterans↗